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Herein we report on the findings of a 2013 Yale Peabody Museum collecting trip to deposits of the New Haven Formation exposed in a former quarry in the Fair Haven Heights neighborhood of New Haven, Connecticut. Two slabs, each bearing a set of shallow (less than 1 cm deep) impressions initially suspected to represent aetosauriform dermal armor, were cut from poorly sorted, matrix-supported conglomeratic boulders. To determine whether they were organic or inorganic in nature, the impressions were examined using high-resolution photography and photogrammetric modeling and analysis using the software Metashape Professional and Cloud-Compare, respectively. Then we tentatively identified features and obtained measurements that allowed us to determine the likely identities of each impression set. While we conclude that one set is most likely the impression of a detached corrugated clast (possibly a differentially weathered banded granite gneiss cobble), the other may represent an incomplete column (three rows long) of small (3–5 cm wide) aetosauriform dorsal paramedian (and potentially two lateral) scutes or osteoderms from the animal's trunk. We tentatively assign the latter impression set to a corresponding body region of a range of potential aetosauriform morphotypes. Despite its discovery near the type locality of the aetosaur Stegomus arcuatus Marsh 1896, we refrain from assigning this new potential aetosauriform specimen to any particular genus or species due to its lack of diagnosable features and concerns about the taxonomic validity of S. arcuatus itself. The coarseness of the sediment in which all three specimens are preserved suggests a high-energy fluvial or alluvial depositional paleoenvironment. As the first potential fossil discovered in New Haven in over a century, we note the local significance of this find and the increasing local interest in the area's paleontological history in the hopes that this discovery may lead to more extensive paleontological and geological surveys within the quarry and the adjacent Quarry Park Preserve.